<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        .box{
            width:400px;
            height: 600px;
            background: cadetblue;
            margin: 20px auto;
            display: -webkit-flex;
            display: flex;

        }

        .son{
            width:120px;
            height: 80px;
            background: darkgreen;
            text-align: center;
            line-height: 50px;
            color:salmon;
        }
        .son:nth-child(1){
            background: indianred;
            flex-shrink: 0;
        }
        .son:nth-child(2){
            background: darkcyan;
            flex-shrink: 3;
        }
        .son:nth-child(3){background: yellow;}
        .son:nth-child(4){background: antiquewhite;}
        .son:nth-child(5){background: darkgoldenrod;}
    </style>
</head>
<body>
<div class="box">
    <div class="son">n1</div>
    <div class="son">n2</div>
    <div class="son">n3</div>
    <div class="son">n4</div>
    <div class="son">n5</div>

</div>
</body>
</html>